[Mod Support] Add support for loading data from zipped packages

[hogsy]

Further extension for modification support etc. drop-in packages which include new models, sounds and other content could be done this way and easily removed if the user chooses not to have them anymore.

Typically would expect the implementation to load from the given mod directory (e.g. 'how') and then any packages there will have been indexed prior.

How will priority work though?

Can use miniz for zip implementation.

[hogsy]

Marked as in-progress because this can be automatically supported when virtual filesystem is utilised.

[hogsy]

Closing, will automatically be supported going forward